With the widespread use of the Internet, information is commonly transmitted via WWW (World Wide Web), etc., in recent years. Under such a circumstance, an image sensing apparatus has emerged which has functions of taking images in real time and delivering the images over a network.
On the other hand, when a camera image delivery service is provided for a user over a network, there is a proposal on a delivery of image data suitable for an environment on the user side.
Japanese Patent Laid-Open No. 2001-197458 describes an image processing apparatus in which information (amount of γ correction) specific to a display (CRT, LCD, etc., as a PC monitor) for an image display on the user side is transmitted to a camera and the camera processes and delivers a taken image based on the information. Japanese Patent Laid-Open No. 2001-197458 is intended to display an image estimated to be most preferable for the display to display an image on the user side.
Furthermore, Japanese Patent Laid-Open No. 2004-151167 describes a server which receives information obtained by measuring a luminance characteristic specific to a display (display of a cellular phone) for each display, carries out an image correction according to the characteristic of each display (display of a cellular phone) and then carries out delivery processing.
Furthermore, a video delivery apparatus described in Japanese Patent Laid-Open No. 2003-319364 stores images taken by a camera in a specific image generation server once. The video delivery apparatus delivers motion images extracted at angles of view requested by a plurality of users who access a specific WEB server via the Internet to the users via the WEB server.
The structure described in Japanese Patent Laid-Open No. 2001-197458 is designed to transmit information specific to a display of a delivery destination to a camera side and reflect the information when taking images using the camera. However, when a plurality of users access one camera, such a structure can only meet a request from a user who has first priority. That is, users who do not have the first priority only view images manipulated by the user who has the first priority and have to display image data adapted to the display of the user who has the first priority.
To meet requests from a plurality of users for concurrent image taking, a structure having a plurality of image processing sections may be conceived. However, in such a case, the contents that can be serviced may be restricted by the number of such processing units. Increasing the number of processing units eases the restrictions. However, a network camera server, etc., which assumes the function on the image-taking side of a video delivery system is generally required to be smaller in size and the number of processing units that can be mounted therein is limited to the areas of the substrate/chip or heat value, etc. For that reason, there is a problem that the number of such processing units is actually limited.
Furthermore, as the case with the technology described in Japanese Patent Laid-Open No. 2003-319364, according to the structure whereby an image of a camera is stored in a server and then the image is processed according to the user's request and transmitted, the image is delivered after being stored and subjected to predetermined processing. For this reason, there is a problem that a considerable difference is produced between the time at which the image is taken and the time at which the image is reproduced. This problem is serious in the case where motion images are taken and those motion images are used at remote places for monitoring purposes, etc., at a plurality of locations with primary importance placed on the real-time nature by a plurality of users. Meeting such purposes requires a system that subjects non-encoded images consisting of 30 frames per sec entering from the image sensing apparatus to processing according to a plurality of requests in a non-encoded state, then encodes the images individually in their respective formats requested and transmits the images. Therefore, the number of users to whom the images can be delivered simultaneously is significantly limited.
On the other hand, it is possible to consider a structure in which images output from a camera are subjected to some irreversible encoding processing and stored in a server, or images delivered from a camera as analog images are converted to digital signals and stored in the server. However, according to such a structure, images obtained by reading encoded data from the server and decoding the data or images subjected to digital to analog conversion and then analog to digital conversion are processed. For this reason, there is a problem that image quality obviously deteriorates compared to a case where non-encoded or non-converted images are processed.
Furthermore, the technology described in Japanese Patent Laid-Open No. 2004-151167 is limited to a case where a limited display device (LCD) such as a cellular phone is used, and cannot be applied to an unspecified majority of types of displays.